CVE-2002-1591 in Instant Messenger
Summary
by MITRE
AOL Instant Messenger (AIM) 4.7.2480 adds free.aol.com to the Trusted Sites Zone in Internet Explorer without user approval, which could allow code from free.aol.com to bypass intended access restrictions.
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Analysis
by VulDB Data Team • 04/23/2025
This vulnerability in AOL Instant Messenger version 4.7.2480 represents a significant security flaw that demonstrates poor privilege management and unauthorized system modification practices. The software automatically adds the free.aol.com domain to Internet Explorer's Trusted Sites zone without explicit user consent, creating an unintended security boundary that undermines the user's control over their browser security settings. This behavior violates fundamental security principles of user consent and system integrity, as it modifies critical browser security configurations without informing or obtaining approval from the end user.
The technical implementation of this vulnerability exploits the trust relationship between Internet Explorer and its security zones by leveraging the legitimate installation process of AIM to perform unauthorized modifications to the browser's security policy. When AIM 4.7.2480 executes, it programmatically alters the Internet Explorer security settings to include the free.aol.com domain in the Trusted Sites zone, which typically grants elevated privileges and reduced security restrictions to websites within that zone. This automatic modification creates a persistent security risk that can be exploited by malicious actors who may attempt to leverage the same technique to gain unauthorized access to systems.
The operational impact of this vulnerability extends beyond the immediate security implications, as it creates a persistent backdoor that can be exploited by attackers who understand the underlying system behavior. Once free.aol.com is added to the Trusted Sites zone, any malicious code hosted on that domain or any domain that can be controlled by attackers can execute with elevated privileges, potentially leading to complete system compromise. The vulnerability also demonstrates a lack of proper sandboxing and privilege separation in the AIM installation process, allowing a third-party application to modify system security settings without proper authorization.
This vulnerability aligns with CWE-276, which addresses improper privileges and access control, and represents a specific instance of unauthorized system modification that violates the principle of least privilege. The security implications can be mapped to ATT&CK technique T1059, which covers command and script interpreters, as the modified security zone can enable malicious code execution through various attack vectors. Organizations and users who installed AIM 4.7.2480 were unknowingly exposed to potential exploitation, as the modification occurred silently during the installation process without user awareness or consent.
The recommended mitigation strategies include immediate removal of the problematic AIM version and manual verification of Internet Explorer security settings to ensure that free.aol.com has not been added to the Trusted Sites zone. System administrators should implement monitoring procedures to detect unauthorized modifications to browser security settings and establish policies that require explicit user consent for any security configuration changes. Additionally, users should be educated about the importance of reviewing security settings after software installation and should regularly audit their browser configurations to identify any unauthorized modifications that may have occurred through similar mechanisms.